J. E. Duserpen—Jamaican Actiniaria: Part I—Zoanthee. 869 
species from various parts of the world, and four doubtful forms. Some of the 
representatives of the genus form incrustations over the surface of univalve shells 
inhabited by hermit-erabs, the shells being ultimately dissolved away. The colony, 
known as a carcinecium, retains somewhat the form of the shell, and contains the 
crustacean still within. 
Epizoanthus minutus, n. sp. 
(PI. xvi. 4, fig. 10.) 
Form.—Polyps cylindrical, rising obliquely or vertically from a thin, incrust- 
ing, ribbon-like coenenchyme. In complete retraction rounded above with a 
small aperture remaining, but no capitular ridges and grooves distinguishable. 
Slightly enlarged towards the base; about the same height as breadth in retrac- 
tion, not much more in extension ; surface rough, covered with very fine sand grains ; 
occasionally with slight transverse wrinklings. In partial retraction swollen and 
flat above, with the wedge-shaped, acute, capitular ridges and furrows visible, and 
the slit-like mouth showing. In full extension the upper part of the column is 
spread out and the middle constricted ; margin of column with fifteen or sixteen or 
twenty-one denticulations, each with parallel sides and a straight free edge, giving 
a castellated appearance. Disc much depressed, cup-shaped, transparent, with lines 
of attachment of mesenteries showing through; mouth elevated. The disc, as 
usual, is divisible into a grooved outer part forming the walls of the cup in exten- 
sion, and appearing as 2 continuation of the united bases of the tentacles, and an 
inner, smooth, flat or slightly elevated, central part bearing the mouth in the 
middle. Tentacles dicyclic, thin, transparent, elongated, slightly swollen and 
rounded at the tips, outer series alternating with the denticulations, entacmzous, 
overhanging in extension, generally thirty or thirty-two in number, but occasion- 
ally forty-two. Coenenchyme thin, incrusting, ribbon-shaped or irregularly 
expanded where the polyps are closer; surface same as that of column-wall. 
Polyps arise independently, and may be considerably separated or more closely 
grouped. 
Colour.—Column-wall and ccenenchyme are a dirty brown, the colour of the 
sand particles; denticulations with white margins; disc brown, with darker 
radiating lines ; tentacles transparent, several series of dark patches are present, 
more pronounced on the outer row, tips almost opaque white. 
Dimensions.—Height of polyps in extension 0°6cm., in contraction 0°35 to 
0-2 cm. Diameter in extension 0°3 cm., in retraction 0°25 to 0°2 em. Length 
of tentacles in full extension 0°4 cm. 
Locality—Found growing in abundance near the margin of one of the 
valves of a living Pinna shell, collected towards the eastern extremity of Kingston 
TRANS. ROY, DUB. SOC., N.S, VOL. VI., PART XIV, 8K 
